Technical Field
The technology disclosed herein relates to a bicycle driving system and a multiple rear sprocket assembly.
Background Information
In a conventional bicycle, a driving system includes a crank assembly and a rear sprocket assembly.
Currently, the conventional rear sprocket assembly includes rear sprockets less than or equal to eleven. The front sprocket drives the rear sprocket assembly via a bicycle chain.
In the configuration of the above driving system, a range of a drive ratio between the front sprocket and the rear sprockets may be sometime insufficient in the case of the rear sprocket assembly including less than or equal to ten rear sprockets.
Also, the length of the rear sprocket assembly (including the rear sprockets) becomes longer than the conventional one in the axial direction if the rear sprocket assembly is designed to include more than or equal to eleven rear sprockets in order that a range of a drive ratio becomes wider. Inclination of the bicycle chain between the crank assembly and the rear sprocket assembly becomes too much when the bicycle chain engages with a largest rear sprocket or a smallest rear sprocket if the axial length of the rear sprocket assembly becomes longer. Such too much inclination of the bicycle chain between the crank assembly and the rear sprocket assembly results in impairing driving efficiency of the driving system.
In consideration of the problem, it is an object of the present invention to provide a bicycle driving system that has a sufficiently wide range of a gear ratio without impairing driving efficiency of the driving system.